Psychiatric comorbidities of chronic migraine in community and tertiary care clinic samples

Chronic Migraine: An Update on Diagnosis and Management

Background

Chronic migraine is an under-recognized and under-treated disorder. A greater understanding of the pathophysiology of migraine and transformation to chronic migraine has led to the first targeted treatments for chronic migraine. In this review, we review current approaches to the diagnosis and management of chronic migraine and discuss recent and emerging novel therapies.

Objective

The aim of this study was to provide an update on the diagnosis and management of chronic migraine.

Methods and Material

The PubMed database was searched for relevant articles published on or before October 2020.

Results and Conclusions

Chronic migraine is an under-recognized and under-treated disorder. Prompt diagnosis and appropriate management can lead to a significant improvement in the quality of life with subsequent socioeconomic benefits.

Prevalence and association of lifestyle and medical-, psychiatric-, and pain-related comorbidities in patients with migraine: A cross-sectional study

BACKGROUND AND OBJECTIVES

Migraine has been associated with many comorbidities. However, lifestyle factors and the presence of comorbid diseases have not previously been extensively studied in the same sample. This study aimed to compare the prevalence of unhealthy lifestyle factors and comorbid diseases between patients with migraine and migraine-free controls with subgroup analyses to determine the pathophysiology and possible consequences.

METHODS

This cross-sectional study recruited 1257 patients with migraine between the ages of 20 and 65 years from a headache outpatient clinic in Taiwan and 496 non-migraine controls. All participants completed questionnaires regarding demographics, migraine diagnosis, sleep, headache burden, and medical, pain, and psychiatric conditions. Participants also underwent a structured interview. The associations between comorbidities and migraine were investigated and further stratified by sex and aura.

RESULTS

Patients with migraine with aura had an unhealthier lifestyle compared with controls in the form of current smoking status (15.5% [67/431] vs. 11.5% [57/496], p = 0.013). Furthermore, medical- (e.g., thyroid disease; 7.2% [91/1257 vs. 2.8% [14/496]; p = 0.006), psychiatric- (e.g., depression; 6% [76/1257 vs. 2.6% [13/496]; p = 0.031), and pain-related (e.g., fibromyalgia; 8% [101/1257 vs. 3.2% [16/496]; p = 0.006) comorbidities were more prevalent in patients compared with controls. Subgroup analyses revealed that chronic migraine, migraine with aura, and female sex were associated with a greater number of significant comorbidities than episodic migraine, migraine without aura, and male patients with migraine, respectively.

CONCLUSION

Individuals seeking treatment for migraine reported greater levels of smoking and medical, psychiatric, and pain conditions than non-treatment-seeking healthy controls who were recruited from the community. Understanding the relationship between migraine and comorbid diseases may improve medical care as well as the quality of life.

Erenumab for the preventive treatment of chronic migraine complicated with medication overuse headache: an observational, retrospective, 12-month real-life study

BACKGROUND

Erenumab is a monoclonal antibody blocking the calcitonin gene-related peptide receptor, which has been approved for the preventive treatment of chronic migraine (CM). The aim of this study was to explore the safety and effectiveness of erenumab in patients suffering from CM and medication overuse headache (MOH) in a real-life setting, up to 1 year.

METHODS

Data regarding 81 patients treated with erenumab were retrospectively analyzed. Every 3 months, the following variables were collected: the mean number of headache days per month (headache index (HI)), the average number of painkillers taken per month (analgesic consumption (AC)), the mean number of days with painkiller consumption (number of days on medication (NDM)), the headache intensity (numeric rating scale (NRS) score), the 6-item Headache Impact Test (HIT-6), and the Self-Reported Instrument to Assess Work-Related Difficulties in Patients With Migraine (HEADWORK) scores.

RESULTS

The HI, AC, and NDM and the NRS, HIT-6, and HEADWORK scores were significantly lower at every time point from the 3rd month onward compared to baseline (all P < 0.0001). No significant differences were found between patients who underwent painkiller detoxification before starting erenumab and those who did not (all P > 0.05). No significant differences were found between patients taking erenumab in combination with other preventive treatments and the ones taking it alone (all P ≥ 0.05). Five patients dropped out because of adverse events, which resolved after stopping erenumab.

CONCLUSION

Erenumab was safe and effective for CM complicated with MOH. Painkiller withdrawal and the association with other preventive treatment(s) seem useless.

Renin-Angiotensin-Aldosterone System and Migraine: A Systematic Review of Human Studies

Migraine is a common neurologic condition marked by recurrent episodes of headache. Its pathophysiology is highly complex involving neuronal, inflammatory and vascular mechanisms. The Renin-Angiotensin System (RAS) can modulate all these mechanism, being a potential pharmacological target for migraine treatment. We carried out a systematic review of the studies evaluating the involvement of RAS in patients with migraine. There is evidence from genetic studies exploring the relation between migraine and RAS-related genes and from clinical trials evaluating the efficacy of Angiotensin II Type 1 (AT1) receptor antagonists and angiotensin converting enzyme inhibitors in migraine prophylaxis. RAS seems to play a role in the pathophysiology of migraine, but more direct evidence is still missing.

Sustained response to onabotulinumtoxin A in patients with chronic migraine: real-life data

Background

Treatment with onabotulinumtoxin A (BT-A) is safe and effective for chronic migraine (CM). Several studies assessed possible predictors of response to treatment with BT-A, but there is little knowledge on the frequency and predictors of sustained response. The aim of this study was to evaluate sustained response to BT-A in patients with CM.

Main body

In this prospective open-label study, 115 patients with CM and treated with BT-A were consecutively enrolled in two Italian headache centers and followed up for 15 months. Anytime responders were defined as those patients who achieved a ≥ 50% reduction in headache days during any three-month treatment cycle compared with the 3 months prior to initiation of BT-A treatment. Sustained responders were defined as those who achieved a ≥ 50% reduction in headache days within the third treatment cycle and maintained response until the end of follow-up. Non-responders were defined as those patients who never achieved a ≥ 50% reduction in headache days during the follow-up. Headache characteristics prior to BT-A treatment were assessed in order to evaluate their ability in predicting treatment response.

The 115 enrolled patients (84.3% female; median age 50 years) had a median migraine duration of 30 years (interquartile range 22–38). At the end of follow-up, 66 patients (57.4%) were classified as anytime responders. Among the 51 patients who achieved a clinical response within the third month of treatment, 33 (64.7%) were sustained responders. Patients with sustained response had a lower CM duration (median 31 vs 65 months; P = 0.030) and a lower number of headache days (median 25 vs 30; P = 0.013) at baseline compared with non-responders.

Conclusions

About two thirds of patients who gain ≥50% response to BT-A within the third cycle of treatment maintain this positive response over time. More recent onset of CM and more headache-free days at baseline are associated with sustained response. We suggest not to delay preventive treatment of CM with BT-A, in order to increase the likelihood to achieve sustained clinical response.

Double-blind placebo-controlled randomized clinical trial of ginger (Zingiber officinale Rosc.) in the prophylactic treatment of migraine

BACKGROUND

Previous studies have shown an analgesic effect of ginger in the acute treatment of migraine, and there is anecdotal evidence of its efficacy in migraine prophylaxis.

OBJECTIVE

This study aimed to evaluate the potential of ginger to prevent migraine attacks.

METHODS

This double-blind, placebo-controlled randomized clinical trial took place at the Headache Clinic, Universidade Federal de Minas Gerais (Belo Horizonte, Minas Gerais, Brazil), involving 107 patients. Only subjects diagnosed with episodic migraine, aged between 18 and 60 years old, and who were not taking any prophylactic medication, were enrolled in the study. After one month of observation, subjects selected for the study were randomized 1:1 into placebo and treatment groups. Patients received capsules three times per day of 200 mg of dry extract of ginger (5% active ingredient) or placebo (cellulose) for three months. Visits were performed monthly and the patients were asked to fill in a migraine diary. The adherence to treatment was evaluated by counting capsules.

RESULTS

The percentage of patients who responded to treatment (i.e. a reduction of 50% in the number of migraine attacks at the end of treatment) did not differ between the groups. There was a decrease in the number of days with severe pain, analgesic use for acute migraine and duration of migraine attacks in both groups, without significant difference between ginger and placebo groups.

CONCLUSIONS

Ginger provides no greater benefit in the prophylactic treatment of migraine when compared to placebo. This trial is registered at ClinicalTrials.gov (NCT02570633).

Prevalence and comorbidity of migraine headache: results from the Singapore Mental Health Study 2016

BACKGROUND AND AIM

Migraine is a highly prevalent and disabling neurological disorder associated with a wide range of psychiatric comorbidities. Studies have revealed that those with migraine headache and coexisting psychiatric disorders have poorer treatment outcomes and increased disability. The study aims to establish the prevalence, correlates, and comorbidities of migraine headache among the multi-ethnic Asian population in Singapore.

METHOD

Data were extracted from the Singapore Mental Health Study 2016 (SMHS 2016), a cross-sectional epidemiological survey of a nationally representative sample. Face-to-face interviews were completed with 6126 participants between 2016 and 2017. The data relating to chronic medical conditions, psychiatric conditions, and 30-day functioning and disability were captured using the World Mental Health Composite International Diagnostic Interview (CIDI) version 3.0.

RESULTS

The lifetime prevalence for migraine headache in the Singapore general population was 8.2%. Malay ethnicity (versus Chinese), female gender (versus male), and diploma holders (versus university) were significantly more likely to experience migraine headache. Participants belonging to the older age group (65 years and above versus 18-34 years of age), and those who were economically inactive (versus employed) were less likely to experience migraine headache. The mean age of onset for migraine was 26.4 years (SD = 11.1). Poisson regression analyses showed that migraine headache was also significantly associated with psychiatric conditions such as major depressive disorder (MDD) (prevalence ratio (PR), 1.80; 95% CI, 1.25-2.58), bipolar disorder (BD) (PR, 3.55; 95% CI, 2.29-5.51), generalized anxiety disorder (GAD) (PR, 2.04; 95% CI, 1.12-3.69), obsessive compulsive disorder (OCD) (PR, 2.20; 95% CI, 1.49-3.26), and alcohol use disorder (AUD) (PR, 1.93; 95% CI, 1.20-3.08). Those with migraine headache were significantly associated with poor functioning and disability compared to those without migraine headache.

CONCLUSIONS AND DISCUSSION

Our study showed significant associations between migraine headache and psychiatric disorders, as well as with role functioning and disability. The findings of our study emphasise the need for screening for psychiatric comorbidity among those with migraine and the development of appropriate interventions for this group.

Nutritional intervention may improve migraine severity: a pilot study

OBJECTIVE

Although some studies have investigated the role of nutritional intervention on migraine, they had focused on triggers or on weight change and, to the best of our knowledge, none studied diet quality.

OBJECTIVE

To investigate whether nutritional intervention focused on improving diet quality and healthy weight can promote improvement in clinical parameters of women with migraine.

METHODS

Non-controlled and non-randomized intervention study conducted for 90 days. Women received an individualized diet meal plan and nutritional orientation according to their nutritional diagnosis. Anthropometric, clinical and nutritional data were measured once a month. Diet energy content and macronutrients were evaluated using 24-hour dietary recall. Diet quality was assessed through the Brazilian Healthy Eating Index-Revised (BHEI-R). The Migraine Disability Assessment and Headache Impact Test version 6 were used to assess the severity of migraine, and the Beck Depression Inventory evaluated depressive symptoms.

RESULTS

Fifty-two women aged 44.0 ± 13.0 years were enrolled. Anthropometric characteristics, energy, macronutrients and fiber intake did not change after intervention. However, the BHEI-R scores improved after 60 and 90 days of intervention. Concurrent to this, the Beck Depression Inventory scores and Headache Impact Test scores decreased after 60 and 90 days, respectively. The change in the BHEI-R score was negatively correlated with the migraine severity as assessed by the Headache Impact Test at the end of the intervention.

CONCLUSIONS

We concluded that the management of diet quality may be a good strategy for improving migraine severity, regardless of the nutritional status and weight change.

Personality disorders are associated with more severe forms of migraine

To investigate the clinical manifestation, disease course, and prognosis of migraine patients with or without personality disorders. This cross-sectional study evaluated 61 patients with migraine diagnosed according to the criteria of the International Headache Society (IHS). Personality disorders were assessed with the Structured Clinical Interview for DSM-IV (SCID-II). Migraine severity was assessed with the Headache Impact Test-6 (HIT-6). We also used a structured clinical interview to diagnose comorbid mood disorders. Of the 61 patients, 20 (32.8%) had personality disorders. Personality disorders included obsessive-compulsive 14/61 (23.0%), avoidant 6/61 (9.8%), borderline 6/61 (9.8%), paranoid 6/61 (9.8%), schizoid 2/61 (3.3%), histrionic 1/61 (1.6%) and dependent 1/61 (1.6%) types. Compared to migraine patients without personality disorders, comorbidity with any personality disorders was associated with an increased frequency of chronic migraine (p < 0.001) and more severe headache as assessed by the HIT-6 (p < 0.001). Comorbidity with personality disorders was associated with more severe forms of migraine symptoms.

The relationship between alexithymia and headache impact: the role of somatization and pain catastrophizing

PURPOSE

The present study compared psychological factors (i.e., alexithymia, somatization, pain catastrophizing (PC), anxiety, and depression) and QOL for headache patients and headache-free individuals, and examined whether somatization and PC mediate the relationship between alexithymia and headache impact in headache patients.

METHODS

Study participants consisted of 123 headache patients from an outpatient clinic at a university hospital and 124 headache-free individuals in Daegu, Korea. The survey employed the somatization and anxiety subscales of the Symptom Checklist-90-revised, the Patient Health Questionnaire-9, Pain Catastrophizing Scale, Toronto Alexithymia Scale, Short-Form Health survey-8 (SF-8), and the Headache Impact Test-6.

RESULTS

Headache patients showed a higher level of all psychological factors and lower level of two summary scores (physical and mental health) as well as the seven dimensions of the SF-8 compared with headache-free individuals. Examination employing the SPSS Process macro found that the direct effect of alexithymia on headache impact was not significant after controlling for somatization and PC. The total indirect effects of alexithymia on headache impact were significant without anxiety and depression as covariates with the significant indirect effects of alexithymia on headache impact via somatization or via PC as well as via somatization and PC. However, after controlling for anxiety and depression, PC was the only significant pathway through which alexithymia was related to headache impact.

CONCLUSIONS

Headache patients may benefit from interventions aiming at improving psychological factors in order to improve the functioning and QOL of headache patients.

A Narrative Review of Evidence-Based Preventive Options for Chronic Migraine

Chronic migraine is a debilitating disorder that affects 2 % of the global population and imparts a significant societal and economic impact. The cornerstones of chronic migraine management include making an accurate diagnosis, patient education, treatment of comorbid conditions, and selection of an appropriate, evidence-based acute and preventive treatment regimen. Although it is common to treat chronic migraine with preventive medications effective for episodic migraine, a number of treatment options exist with specific evidence for effectiveness in chronic migraine. Currently, onabotulinumtoxinA injections are the only FDA-approved preventive treatment for chronic migraine. A number of non-medication treatment options including occipital nerve and supraorbital nerve stimulation have shown promise as effective prevention for patients either unable to tolerate or unable to obtain relief from oral medications, but more research is necessary.

Associação de sintomas depressivos e ansiosos com gravidade da migrânea

Objetivo O objetivo do presente estudo foi avaliar a associação do sono, depressão e ansiedade em pacientes com migrânea. Métodos Cinquenta pacientes do sexo feminino, provenientes de um centro terciário de tratamento de cefaleias, com o diagnóstico de migrânea segundo os critérios da International Headache Society, foram incluídas neste estudo. As pacientes foram avaliadas com os seguintes instrumentos: Migraine Disability Assessment test (MIDAS), Headache Impact Test (HIT), Hospital Anxiety (HADS-A) and Depression Scale (HAD-D), Índice de Qualidade do Sono de Pittsburgh (IQSP) e Escala de Sonolência de Epworth (ESE). Resultados As pacientes apresentaram alta prevalência de sintomas de ansiedade (60%) e de depressão (42%), má qualidade do sono (80%) e sonolência diurna (36%). Foi demonstrada correlação positiva entre a gravidade dos sintomas de ansiedade e HIT (p = 0,018; ρ = 0,334), ESE (p = 0,002; ρ = 0,426) e IQSP (p = 0,002; ρ = 0,426). Correlação positiva também foi demonstrada entre a gravidade dos sintomas depressivos e HIT (p < 0,001; ρ = 0,532), ESE (p = 0,035; ρ = 0,299) e IQSP (p = 0,016, ρ = 0,34). Não houve associação entre a qualidade do sono, a sonolência diurna e a gravidade da migrânea. A pontuação na HAD-D foi o principal preditor de impacto grave da migrânea. Conclusão Apesar da alta frequência de distúrbios do sono, o principal fator relacionado ao impacto da migrânea foi a gravidade dos sintomas depressivos.

Suicidal ideation and risk factors in Korean migraine patients

Population-based studies have reported an increased risk of suicidal ideation in patients with migraine. However, there is some controversy as to whether migraine itself is a risk factor for suicidal ideation after adjusting for psychiatric comorbidities. We calculated the frequency of suicidal ideation among patients with migraine visiting a tertiary care hospital and determined its risk factors. Patients with migraine and healthy controls completed self-report questionnaires to assess depression, anxiety, and suicidal ideation, and the frequency of suicidal ideation. Risk factors for suicidal ideation were investigated in terms of demographic, clinical, and psychiatric variables. One hundred eighty-five patients with migraine (156 females and 29 males; mean age 39.1 years) and 53 age and education-matched healthy controls participated in the study. The frequency of suicidal ideation was significantly greater in patients with migraine than healthy controls (odds ratio [OR]=5.09, 95% confidence interval [CI] 1.17-22.10, p=0.003), but this significance was not sustained after adjusting for comorbid depression and anxiety. The risk of suicidal ideation in patients with migraine was associated with lower education levels, higher frequency of migraine attacks, stronger intensity of headaches, and presence of phonophobia, chronic migraine, depression, and anxiety. The strongest predictor was depression (OR=15.36, 95% CI 5.39-43.78, p<0.001), followed by the intensity of headache while completing the questionnaire (OR=1.293, 95% CI 1.077-1.553; p=0.006). The contribution of migraine-specific variables to suicidal ideation is trivial compared to that of depression and headache intensity.

Migraine headaches and mood/anxiety disorders in the ELSA Brazil

OBJECTIVE

To describe the relationship between mood/anxiety disorders and migraine headaches emphasizing the frequency of episodes based in a cross-sectional analysis in the Brazilian Longitudinal Study of Adult Health.

BACKGROUND

It has been suggested that frequency of migraine headaches can be directly associated with the presence of psychiatric disorders.

METHODS

Migraine headaches (International Headache Society criteria) was classified as <1×/month, 1×/month-1×/week, 2-6×/week, and daily. Psychiatric disorders using the Clinical Interview Schedule - Revised were classified in 6 categories: common mental (CMD), major depressive (MDD), generalized anxiety (GAD), panic, obsessive-compulsive (OCD), and mixed anxiety and depressive (MADD) disorders. We performed multivariate logistic models adjusted for age, race, education, marital status, income, and use of selective serotonin reuptake inhibitors.

RESULTS

In our sample, 1261 presented definite migraine and 10,531 without migraine headaches (reference). Our main result was an increase in the strength of association between migraine and MDD as frequency of migraine increased for all sample: odds ratio of 2.14 (95% confidence interval [CI] 1.33-3.43) for <1 episode of migraine/month to 6.94 (95% CI 4.20-11.49) for daily headaches for all sample. Significant associations with migraine were also found for GAD, OCD, MADD, and CMD for total sample: MDD, GAD, OCD, MADD, and CMD for women, and MADD and CMD for men. Among men with daily migraine complaint, we found a significant association between migraine and OCD after correction for multiple comparisons (odds ratio 29.86 [95% CI 4.66-191.43]). Analyzing probable and definite migraine cases together, we replicated the findings in a lower magnitude.

CONCLUSIONS

The increase in migraine frequency was associated with progressively higher frequencies of having mood/anxiety disorders in all samples suggesting for some psychiatric disorders a likely dose-response effect especially for women.

Outcome of patients with chronic migraine with medication overuse and depression after duloxetine: influence of coexisting obsessive compulsive disorder

Patients with chronic migraine (CM) and medication overuse (MO) have high frequency of psychiatric comorbidity. Aims of this open label, prospective, independent study were: to evaluate the efficacy of duloxetine in a sample of patients with MO due to CM and with concomitant depression; to investigate, if the presence of OCD influences the outcome in this subgroup of patients. A total of 50 consecutive patients (40 F,10 M, aged 20-65 years, mean 39.4 years) from those attending our Headache Center to undergo an inpatient withdrawal programme followed by anti-migraine prophylaxis was enrolled. After a 1-month baseline period, all patients were prescribed duloxetine 30 mg in the morning for the first week, and 60 mg for the following 12 weeks. They filled a daily headache diary during the whole study period. They also completed Hamilton depression rating scale (HDRS) and migraine disability assessment scale (MIDAS) at baseline and at the 12-week follow-up. The primary outcome measure was the percentage of responders, i.e. of patients with a reduction ≥50 % in headache frequency as well as in symptomatic drug consumption. Comparison between patients with and without OCD was performed. Our results showed a rather high responder rate in the total sample (64 %), while none of the patients with OCD fell among responders. MIDAS and HDRS scores had a more evident decrease in patients without OSD. These findings suggest that duloxetine may be effective in patients with MO due to CM and with comorbid depression. They also confirm the importance of a systematic assessment of the psychopathological profile in these patients, and indicate that clinicians should be aware of the relevant prognostic role of OCD in favoring a poor outcome and persistent disability in headache patients with MO.

Alcohol use problems in migraine and tension-type headache

Objective: The aim of this study was to assess alcohol use problems in patients with migraine and tension-type headache. Method: We evaluated 81 patients with migraine and 62 patients with tension-type headache. The identification of alcohol consumption problems was carried out with Alcohol Use Disorders Identification Test (AUDIT). Alcohol use problem was defined as an AUDIT score of 8 or above. The headache impact was calculated with headache impact test (HIT-6). Results: The proportions of alcohol use problem among patients with migraine and tension-type headache were 5.2% and 16.1%, respectively (P=0.044). The headache impact was significantly higher with migraine than with tension-type headache (P<0.0001). There was an inverse correlation between headache impact and AUDIT (P=0.043). Conclusions: Our results suggest that migraine patients are less prone to alcohol use problems than tension-type headache patients. One of the possible reasons is that migraine is associated with greater impact than tension-type headache.

Latin American consensus on guidelines for chronic migraine treatment

Chronic migraine is a condition with significant prevalence all around the world and high socioeconomic impact, and its handling has been challenging neurologists. Developments for understanding its mechanisms and associated conditions, as well as that of new therapies, have been quick and important, a fact which has motivated the Latin American and Brazilian Headache Societies to prepare the present consensus. The treatment of chronic migraine should always be preceded by a careful diagnosis review; the detection of possible worsening factors and associated conditions; the stratification of seriousness/impossibility to treat; and monitoring establishment, with a pain diary. The present consensus deals with pharmacological and nonpharmacological forms of treatment to be used in chronic migraine.

Greater frequency of depression associated with chronic primary headaches than chronic post-traumatic headaches

OBJECTIVE

To compare the prevalence of co-morbid depression between patients with chronic primary headache syndromes and chronic posttraumatic headaches.

METHOD

A prospective cross-sectional analysis of all patients presenting sequentially to a community-based general neurology clinic during a 2-year period for evaluation of chronic headache pain was conducted. Headache diagnosis was determined according to the International Headache Society's Headache Classification criteria. Depression was determined through a combination of scores on the clinician administered Hamilton Rating Scale for Depression and patients' self-report. An additional group of patients who suffered traumatic brain injuries (TBI) but did not develop post-traumatic headaches was included for comparison.

RESULTS

A total of 83 patients were included in the study: 45 with chronic primary headaches (24 with chronic migraine headaches, 21 with chronic tension headaches), 24 with chronic post-traumatic headaches, and 14 with TBI but no headaches. Depression occurred less frequently among those with chronic post-traumatic headaches (33.3%) compared to those with chronic migraine (66.7%) and chronic tension (52.4%) headaches (Chi-Square = 7.68; df = 3; p = 0.053), and did not significantly differ from TBI patients without headaches. A multivariate logistic regression model using depression as the outcome variable and including headache diagnosis, gender, ethnicity, and alcohol and illicit substance use was statistically significant (Chi-Square = 27.201; df = 10; p < 0.01) and identified primary headache (migraine and tension) diagnoses (Score = 7.349; df = 1; p = 0.04) and female gender (Score = 15.281; df = 1; p < 0.01) as significant predictor variables. The overall model accurately predicted presence of co-morbid depression in 74.7% of the cases.

CONCLUSIONS

Co-morbid depression occurs less frequently among patients with chronic post-traumatic headaches and TBI without headaches than among those with chronic primary headaches.